| Message ID | 1308261747-17702-1-git-send-email-scottjg@vmware.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
LGTM. Signed-off-by: Bhavesh Davda <bhavesh@vmware.com> > -----Original Message----- > From: pv-drivers-bounces@vmware.com [mailto:pv-drivers-bounces@vmware.com] On > Behalf Of Scott J. Goldman > Sent: Thursday, June 16, 2011 3:02 PM > To: netdev@vger.kernel.org; pv-drivers@vmware.com > Subject: [Pv-drivers] [PATCH] vmxnet3: fix starving rx ring when alloc_skb > fails > > if the rx ring is completely empty, then the device may never fire an rx > interrupt. unfortunately, the rx interrupt is what triggers populating > the rx ring with fresh buffers, so this will cause networking to lock > up. > > this patch recycles the last skb that we were about to indicate up to > the network stack (only if the rx ring is completely starved of skbs) > so the ring will never be completely empty. If we fail to allocate a > secondary page buffer, we just indicate a 0 length buffer to the device. > > Signed-off-by: Scott J. Goldman <scottjg@vmware.com> > --- > drivers/net/vmxnet3/vmxnet3_drv.c | 98 +++++++++++++++++++++++++----------- > drivers/net/vmxnet3/vmxnet3_int.h | 5 +- > 2 files changed, 70 insertions(+), 33 deletions(-) > > diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c > b/drivers/net/vmxnet3/vmxnet3_drv.c > index 33097ec..cfa9ff7 100644 > --- a/drivers/net/vmxnet3/vmxnet3_drv.c > +++ b/drivers/net/vmxnet3/vmxnet3_drv.c > @@ -558,6 +558,17 @@ vmxnet3_tq_cleanup_all(struct vmxnet3_adapter *adapter) > vmxnet3_tq_cleanup(&adapter->tx_queue[i], adapter); > } > > +static bool > +vmxnet3_rq_empty(const struct vmxnet3_rx_queue *rq, u32 ring_idx) > +{ > + const struct vmxnet3_cmd_ring *ring = &rq->rx_ring[ring_idx]; > + u32 i = ring->next2comp; > + while (rq->buf_info[ring_idx][i].buf_type != VMXNET3_RX_BUF_SKB) > + VMXNET3_INC_RING_IDX_ONLY(i, ring->size); > + > + return (i == ring->next2fill); > +} > + > /* > * starting from ring->next2fill, allocate rx buffers for the given ring > * of the rx queue and update the rx desc. stop after @num_to_alloc > buffers > @@ -571,9 +582,12 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 > ring_idx, > int num_allocated = 0; > struct vmxnet3_rx_buf_info *rbi_base = rq->buf_info[ring_idx]; > struct vmxnet3_cmd_ring *ring = &rq->rx_ring[ring_idx]; > + struct vmxnet3_rx_ctx *ctx = &rq->rx_ctx; > + bool alloc_skb_failed = false; > u32 val; > + u32 len; > > - while (num_allocated < num_to_alloc) { > + while (num_allocated < num_to_alloc && !alloc_skb_failed) { > struct vmxnet3_rx_buf_info *rbi; > union Vmxnet3_GenericDesc *gd; > > @@ -586,7 +600,27 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 > ring_idx, > NET_IP_ALIGN); > if (unlikely(rbi->skb == NULL)) { > rq->stats.rx_buf_alloc_failure++; > - break; > + alloc_skb_failed = true; > + /* > + * if allocation failed and ring is > + * empty, we recycle the last skb we > + * rx'ed so that we don't starve the > + * rx ring > + */ > + if (ctx->skb && > + vmxnet3_rq_empty(rq, ring_idx)) { > + rbi->skb = ctx->skb; > + ctx->skb = NULL; > + skb_recycle_check(rbi->skb, > + rbi->len + > + NET_IP_ALIGN); > + /* > + * free any frags chained to > + * the skb > + */ > + __pskb_trim(rbi->skb, 0); > + } else > + break; > } > rbi->skb->dev = adapter->netdev; > > @@ -594,8 +628,10 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 > ring_idx, > rbi->dma_addr = pci_map_single(adapter->pdev, > rbi->skb->data, rbi->len, > PCI_DMA_FROMDEVICE); > + len = rbi->len; > } else { > /* rx buffer skipped by the device */ > + len = rbi->len; > } > val = VMXNET3_RXD_BTYPE_HEAD << VMXNET3_RXD_BTYPE_SHIFT; > } else { > @@ -606,13 +642,18 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 > ring_idx, > rbi->page = alloc_page(GFP_ATOMIC); > if (unlikely(rbi->page == NULL)) { > rq->stats.rx_buf_alloc_failure++; > - break; > + len = 0; > + } else { > + rbi->dma_addr = pci_map_page( > + adapter->pdev, > + rbi->page, 0, > + PAGE_SIZE, > + PCI_DMA_FROMDEVICE); > + len = rbi->len; > } > - rbi->dma_addr = pci_map_page(adapter->pdev, > - rbi->page, 0, PAGE_SIZE, > - PCI_DMA_FROMDEVICE); > } else { > /* rx buffers skipped by the device */ > + len = rbi->len; > } > val = VMXNET3_RXD_BTYPE_BODY << VMXNET3_RXD_BTYPE_SHIFT; > } > @@ -620,7 +661,7 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 > ring_idx, > BUG_ON(rbi->dma_addr == 0); > gd->rxd.addr = cpu_to_le64(rbi->dma_addr); > gd->dword[2] = cpu_to_le32((ring->gen << VMXNET3_RXD_GEN_SHIFT) > - | val | rbi->len); > + | val | len); > > num_allocated++; > vmxnet3_cmd_ring_adv_next2fill(ring); > @@ -1148,7 +1189,6 @@ vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq, > &rxComp); > while (rcd->gen == rq->comp_ring.gen) { > struct vmxnet3_rx_buf_info *rbi; > - struct sk_buff *skb; > int num_to_alloc; > struct Vmxnet3_RxDesc *rxd; > u32 idx, ring_idx; > @@ -1168,7 +1208,7 @@ vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq, > rbi = rq->buf_info[ring_idx] + idx; > > BUG_ON(rxd->addr != rbi->dma_addr || > - rxd->len != rbi->len); > + (rxd->len != rbi->len && rbi->len != 0)); > > if (unlikely(rcd->eop && rcd->err)) { > vmxnet3_rx_error(rq, rcd, ctx, adapter); > @@ -1198,8 +1238,7 @@ vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq, > PCI_DMA_FROMDEVICE); > > skb_put(ctx->skb, rcd->len); > - } else { > - BUG_ON(ctx->skb == NULL); > + } else if (ctx->skb) { > /* non SOP buffer must be type 1 in most cases */ > if (rbi->buf_type == VMXNET3_RX_BUF_PAGE) { > BUG_ON(rxd->btype != VMXNET3_RXD_BTYPE_BODY); > @@ -1222,25 +1261,6 @@ vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq, > } > } > > - skb = ctx->skb; > - if (rcd->eop) { > - skb->len += skb->data_len; > - skb->truesize += skb->data_len; > - > - vmxnet3_rx_csum(adapter, skb, > - (union Vmxnet3_GenericDesc *)rcd); > - skb->protocol = eth_type_trans(skb, adapter->netdev); > - > - if (unlikely(adapter->vlan_grp && rcd->ts)) { > - vlan_hwaccel_receive_skb(skb, > - adapter->vlan_grp, rcd->tci); > - } else { > - netif_receive_skb(skb); > - } > - > - ctx->skb = NULL; > - } > - > rcd_done: > /* device may skip some rx descs */ > rq->rx_ring[ring_idx].next2comp = idx; > @@ -1264,6 +1284,24 @@ rcd_done: > } > } > > + if (rcd->eop && ctx->skb) { > + ctx->skb->len += ctx->skb->data_len; > + ctx->skb->truesize += ctx->skb->data_len; > + > + vmxnet3_rx_csum(adapter, ctx->skb, > + (union Vmxnet3_GenericDesc *)rcd); > + ctx->skb->protocol = eth_type_trans(ctx->skb, > + adapter->netdev); > + if (unlikely(adapter->vlan_grp && rcd->ts)) { > + vlan_hwaccel_receive_skb(ctx->skb, > + adapter->vlan_grp, > + rcd->tci); > + } else { > + netif_receive_skb(ctx->skb); > + } > + ctx->skb = NULL; > + } > + > vmxnet3_comp_ring_adv_next2proc(&rq->comp_ring); > vmxnet3_getRxComp(rcd, > &rq->comp_ring.base[rq->comp_ring.next2proc].rcd, &rxComp); > diff --git a/drivers/net/vmxnet3/vmxnet3_int.h > b/drivers/net/vmxnet3/vmxnet3_int.h > index 0e567c24..cb13ed7 100644 > --- a/drivers/net/vmxnet3/vmxnet3_int.h > +++ b/drivers/net/vmxnet3/vmxnet3_int.h > @@ -68,10 +68,10 @@ > /* > * Version numbers > */ > -#define VMXNET3_DRIVER_VERSION_STRING "1.1.9.0-k" > +#define VMXNET3_DRIVER_VERSION_STRING "1.1.10.0-k" > > /* a 32-bit int, each byte encode a verion number in VMXNET3_DRIVER_VERSION > */ > -#define VMXNET3_DRIVER_VERSION_NUM 0x01010900 > +#define VMXNET3_DRIVER_VERSION_NUM 0x01010A00 > > #if defined(CONFIG_PCI_MSI) > /* RSS only makes sense if MSI-X is supported. */ > @@ -255,7 +255,6 @@ struct vmxnet3_rx_buf_info { > > struct vmxnet3_rx_ctx { > struct sk_buff *skb; > - u32 sop_idx; > }; > > struct vmxnet3_rq_driver_stats { > -- > 1.7.4.1 > > _______________________________________________ > Pv-drivers mailing list > Pv-drivers@vmware.com > http://mailman2.vmware.com/mailman/listinfo/pv-drivers -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: "Scott J. Goldman" <scottjg@vmware.com> Date: Thu, 16 Jun 2011 15:02:27 -0700 > if the rx ring is completely empty, then the device may never fire an rx > interrupt. unfortunately, the rx interrupt is what triggers populating > the rx ring with fresh buffers, so this will cause networking to lock > up. > > this patch recycles the last skb that we were about to indicate up to > the network stack (only if the rx ring is completely starved of skbs) > so the ring will never be completely empty. If we fail to allocate a > secondary page buffer, we just indicate a 0 length buffer to the device. > > Signed-off-by: Scott J. Goldman <scottjg@vmware.com> This is why other drivers allocate the replacement skb _first_ before handing the current receive packet to the stack. And if the replacement allocation fails, they elide passing the packet to the stack, and instead recycle it back onto the RX ring. Please implement your RX policy in this manner, as we advise all Linux networking drivers to, and you simply won't have this problem. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi David. > This is why other drivers allocate the replacement skb _first_ before > handing the current receive packet to the stack. > > And if the replacement allocation fails, they elide passing the packet > to the stack, and instead recycle it back onto the RX ring. > > Please implement your RX policy in this manner, as we advise all Linux > networking drivers to, and you simply won't have this problem. I'm sorry if my patch description was unclear, but as I understand it, what you are describing is what this patch implements. The patched rx handler does something like: 1) poll the rx ring, peel off a pending skb (don't pass the packet up the stack yet) 2) if the ring needs to be repopulated, we do that 3) if the ring was repopulated successfully, then that's great, and we pass up the pending skb to the network stack. 4) if not and there are no skbs left on the ring, we reuse the pending skb and recycle it back on the ring (effectively dropping the packet we were about to pass up to the network stack) Maybe the code structure is a bit unclear? Since we don't always repopulate the ring every iteration (only when we hit a low watermark), it's true that we don't strictly always allocate a new skb before passing up the old one, but since this is only a problem when there are no skbs on the ring, and we do elide passing up the pending skb in this case, is that not ok? thanks, -sjg-- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Scott Goldman <scottjg@vmware.com> Date: Thu, 16 Jun 2011 21:40:15 -0700 > I'm sorry if my patch description was unclear, but as I understand it, what you are describing is what this patch implements. The patched rx handler does something like: > 1) poll the rx ring, peel off a pending skb (don't pass the packet up the stack yet) > 2) if the ring needs to be repopulated, we do that > 3) if the ring was repopulated successfully, then that's great, and we pass up the pending skb to the network stack. > 4) if not and there are no skbs left on the ring, we reuse the pending skb and recycle it back on the ring (effectively dropping the packet we were about to pass up to the network stack) You shouldn't restrict this logic to when the ring is empty, you should never leave any RX ring slots empty. Every RX ring entry should be processed with a "alloc_skb()" first, and if the allocation fails you recycle the RX ring's SKB. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, 2011-06-17 at 00:53 -0400, David Miller wrote: > From: Scott Goldman <scottjg@vmware.com> > Date: Thu, 16 Jun 2011 21:40:15 -0700 > > > I'm sorry if my patch description was unclear, but as I understand it, what you are describing is what this patch implements. The patched rx handler does something like: > > 1) poll the rx ring, peel off a pending skb (don't pass the packet up the stack yet) > > 2) if the ring needs to be repopulated, we do that > > 3) if the ring was repopulated successfully, then that's great, and we pass up the pending skb to the network stack. > > 4) if not and there are no skbs left on the ring, we reuse the pending skb and recycle it back on the ring (effectively dropping the packet we were about to pass up to the network stack) > > You shouldn't restrict this logic to when the ring is empty, you > should never leave any RX ring slots empty. > > Every RX ring entry should be processed with a "alloc_skb()" first, > and if the allocation fails you recycle the RX ring's SKB. But this means the driver drops received packets as soon as there is an allocation failure, rather than only if there are repeated failures. I don't see how that's preferable. Ben.
From: Ben Hutchings <bhutchings@solarflare.com> Date: Fri, 17 Jun 2011 13:14:20 +0100 > But this means the driver drops received packets as soon as there is an > allocation failure, rather than only if there are repeated failures. I > don't see how that's preferable. Because it decreases the possibility of RX ring starvation. If you get one allocation failure during a NAPI poll run, and you're proabably processing a set of packets, they are all going to fail. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c index 33097ec..cfa9ff7 100644 --- a/drivers/net/vmxnet3/vmxnet3_drv.c +++ b/drivers/net/vmxnet3/vmxnet3_drv.c @@ -558,6 +558,17 @@ vmxnet3_tq_cleanup_all(struct vmxnet3_adapter *adapter) vmxnet3_tq_cleanup(&adapter->tx_queue[i], adapter); } +static bool +vmxnet3_rq_empty(const struct vmxnet3_rx_queue *rq, u32 ring_idx) +{ + const struct vmxnet3_cmd_ring *ring = &rq->rx_ring[ring_idx]; + u32 i = ring->next2comp; + while (rq->buf_info[ring_idx][i].buf_type != VMXNET3_RX_BUF_SKB) + VMXNET3_INC_RING_IDX_ONLY(i, ring->size); + + return (i == ring->next2fill); +} + /* * starting from ring->next2fill, allocate rx buffers for the given ring * of the rx queue and update the rx desc. stop after @num_to_alloc buffers @@ -571,9 +582,12 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 ring_idx, int num_allocated = 0; struct vmxnet3_rx_buf_info *rbi_base = rq->buf_info[ring_idx]; struct vmxnet3_cmd_ring *ring = &rq->rx_ring[ring_idx]; + struct vmxnet3_rx_ctx *ctx = &rq->rx_ctx; + bool alloc_skb_failed = false; u32 val; + u32 len; - while (num_allocated < num_to_alloc) { + while (num_allocated < num_to_alloc && !alloc_skb_failed) { struct vmxnet3_rx_buf_info *rbi; union Vmxnet3_GenericDesc *gd; @@ -586,7 +600,27 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 ring_idx, NET_IP_ALIGN); if (unlikely(rbi->skb == NULL)) { rq->stats.rx_buf_alloc_failure++; - break; + alloc_skb_failed = true; + /* + * if allocation failed and ring is + * empty, we recycle the last skb we + * rx'ed so that we don't starve the + * rx ring + */ + if (ctx->skb && + vmxnet3_rq_empty(rq, ring_idx)) { + rbi->skb = ctx->skb; + ctx->skb = NULL; + skb_recycle_check(rbi->skb, + rbi->len + + NET_IP_ALIGN); + /* + * free any frags chained to + * the skb + */ + __pskb_trim(rbi->skb, 0); + } else + break; } rbi->skb->dev = adapter->netdev; @@ -594,8 +628,10 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 ring_idx, rbi->dma_addr = pci_map_single(adapter->pdev, rbi->skb->data, rbi->len, PCI_DMA_FROMDEVICE); + len = rbi->len; } else { /* rx buffer skipped by the device */ + len = rbi->len; } val = VMXNET3_RXD_BTYPE_HEAD << VMXNET3_RXD_BTYPE_SHIFT; } else { @@ -606,13 +642,18 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 ring_idx, rbi->page = alloc_page(GFP_ATOMIC); if (unlikely(rbi->page == NULL)) { rq->stats.rx_buf_alloc_failure++; - break; + len = 0; + } else { + rbi->dma_addr = pci_map_page( + adapter->pdev, + rbi->page, 0, + PAGE_SIZE, + PCI_DMA_FROMDEVICE); + len = rbi->len; } - rbi->dma_addr = pci_map_page(adapter->pdev, - rbi->page, 0, PAGE_SIZE, - PCI_DMA_FROMDEVICE); } else { /* rx buffers skipped by the device */ + len = rbi->len; } val = VMXNET3_RXD_BTYPE_BODY << VMXNET3_RXD_BTYPE_SHIFT; } @@ -620,7 +661,7 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 ring_idx, BUG_ON(rbi->dma_addr == 0); gd->rxd.addr = cpu_to_le64(rbi->dma_addr); gd->dword[2] = cpu_to_le32((ring->gen << VMXNET3_RXD_GEN_SHIFT) - | val | rbi->len); + | val | len); num_allocated++; vmxnet3_cmd_ring_adv_next2fill(ring); @@ -1148,7 +1189,6 @@ vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq, &rxComp); while (rcd->gen == rq->comp_ring.gen) { struct vmxnet3_rx_buf_info *rbi; - struct sk_buff *skb; int num_to_alloc; struct Vmxnet3_RxDesc *rxd; u32 idx, ring_idx; @@ -1168,7 +1208,7 @@ vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq, rbi = rq->buf_info[ring_idx] + idx; BUG_ON(rxd->addr != rbi->dma_addr || - rxd->len != rbi->len); + (rxd->len != rbi->len && rbi->len != 0)); if (unlikely(rcd->eop && rcd->err)) { vmxnet3_rx_error(rq, rcd, ctx, adapter); @@ -1198,8 +1238,7 @@ vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq, PCI_DMA_FROMDEVICE); skb_put(ctx->skb, rcd->len); - } else { - BUG_ON(ctx->skb == NULL); + } else if (ctx->skb) { /* non SOP buffer must be type 1 in most cases */ if (rbi->buf_type == VMXNET3_RX_BUF_PAGE) { BUG_ON(rxd->btype != VMXNET3_RXD_BTYPE_BODY); @@ -1222,25 +1261,6 @@ vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq, } } - skb = ctx->skb; - if (rcd->eop) { - skb->len += skb->data_len; - skb->truesize += skb->data_len; - - vmxnet3_rx_csum(adapter, skb, - (union Vmxnet3_GenericDesc *)rcd); - skb->protocol = eth_type_trans(skb, adapter->netdev); - - if (unlikely(adapter->vlan_grp && rcd->ts)) { - vlan_hwaccel_receive_skb(skb, - adapter->vlan_grp, rcd->tci); - } else { - netif_receive_skb(skb); - } - - ctx->skb = NULL; - } - rcd_done: /* device may skip some rx descs */ rq->rx_ring[ring_idx].next2comp = idx; @@ -1264,6 +1284,24 @@ rcd_done: } } + if (rcd->eop && ctx->skb) { + ctx->skb->len += ctx->skb->data_len; + ctx->skb->truesize += ctx->skb->data_len; + + vmxnet3_rx_csum(adapter, ctx->skb, + (union Vmxnet3_GenericDesc *)rcd); + ctx->skb->protocol = eth_type_trans(ctx->skb, + adapter->netdev); + if (unlikely(adapter->vlan_grp && rcd->ts)) { + vlan_hwaccel_receive_skb(ctx->skb, + adapter->vlan_grp, + rcd->tci); + } else { + netif_receive_skb(ctx->skb); + } + ctx->skb = NULL; + } + vmxnet3_comp_ring_adv_next2proc(&rq->comp_ring); vmxnet3_getRxComp(rcd, &rq->comp_ring.base[rq->comp_ring.next2proc].rcd, &rxComp); diff --git a/drivers/net/vmxnet3/vmxnet3_int.h b/drivers/net/vmxnet3/vmxnet3_int.h index 0e567c24..cb13ed7 100644 --- a/drivers/net/vmxnet3/vmxnet3_int.h +++ b/drivers/net/vmxnet3/vmxnet3_int.h @@ -68,10 +68,10 @@ /* * Version numbers */ -#define VMXNET3_DRIVER_VERSION_STRING "1.1.9.0-k" +#define VMXNET3_DRIVER_VERSION_STRING "1.1.10.0-k" /* a 32-bit int, each byte encode a verion number in VMXNET3_DRIVER_VERSION */ -#define VMXNET3_DRIVER_VERSION_NUM 0x01010900 +#define VMXNET3_DRIVER_VERSION_NUM 0x01010A00 #if defined(CONFIG_PCI_MSI) /* RSS only makes sense if MSI-X is supported. */ @@ -255,7 +255,6 @@ struct vmxnet3_rx_buf_info { struct vmxnet3_rx_ctx { struct sk_buff *skb; - u32 sop_idx; }; struct vmxnet3_rq_driver_stats {
if the rx ring is completely empty, then the device may never fire an rx interrupt. unfortunately, the rx interrupt is what triggers populating the rx ring with fresh buffers, so this will cause networking to lock up. this patch recycles the last skb that we were about to indicate up to the network stack (only if the rx ring is completely starved of skbs) so the ring will never be completely empty. If we fail to allocate a secondary page buffer, we just indicate a 0 length buffer to the device. Signed-off-by: Scott J. Goldman <scottjg@vmware.com> --- drivers/net/vmxnet3/vmxnet3_drv.c | 98 +++++++++++++++++++++++++----------- drivers/net/vmxnet3/vmxnet3_int.h | 5 +- 2 files changed, 70 insertions(+), 33 deletions(-)